The present invention relates to a three-dimensional (3D) image processing technique of applying a specified image processing to display a model located in a simulated 3D space on a monitor after rendering it, which technique is applied, for example, to video game systems and computer graphics (CG) images.
In recent years, various game systems in which characters are displayed in a simulated 3D space generated on a monitor screen have been spread. Some of such game systems are known to simulate car race, skiing, surfing, motor-booting, snow boarding, skate boarding, etc.
Further, in these games in which a character runs (or slides) on a ground surface or water surface, the presence of the game largely differs depending on how realistically a change in a background image resulting from the character""s movement is expressed.
Particularly, in a car race game in which a character drives on a dirt course, a skiing or snow board game in which a character slides on a slope or a CG image, a better presence can be given if a trace formed on the ground as the character drives (or slides) is created, with the result that games and CG images rich in ingenuity can be realized.
In view of the above situation, an object of the present invention is to provide image processing method and apparatus for realistically and easily creating a trace formed on a ground surface or water surface as a character drives or slides, a readable storage medium storing a 3D image processing program and a video game system.
In order to achieve the above object, according to the present invention, a three-dimensional image processing apparatus for creating an image of a trace having a width and formed on a ground surface or a water surface as a 3-D model (three dimensional model) having a width moves in contact with the ground surface or the water surface, which comprises position calculating means for calculating positions at opposite widthwise sides where the trace is to be created at specified time intervals, polygon generating means for generating polygons for the trace by successively determining the calculated positions at the opposite widthwise sides as vertices, polygon storage means for storing the generated polygons, texture storage means for storing textures to be adhered to the polygons, and texture adhering means for adhering the textures stored in the texture storage means to the polygons. With the above construction, the polygons for the trace can be easily generated by successively determining, as the respective vertices, the positions at the opposite widthwise sides where the trace is to be created. An image of the trace can be realistically and easily created by adhering the textures to these polygons.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings.